When bulk mailings are made, significant discounts may be obtained by addressing the items to be mailed in a particular order. For example, postal discounts may be obtained by grouping all mailings destined for a particular zip code or, more generally, mailings destined for the same geographic area. Bulk mailers have long recognized the postage discounts associated with organized mailing and have typically personalized mailings so that as the mailings emerge from a printing line, the mailings are presorted.
As the bulk mailing industry has become more sophisticated, many mailers have opted to send a variety of different mailings to potential customers. The different mailing may include catalogs, flyers, etc. that have different physical configurations. For example, some mailings may include different binding styles, trim sizes, or thickness variations. Historically, however, mailings of different physical configurations are produced in separate mail streams due to equipment limitations. For example, a catalog of significant thickness may be processed on equipment different from that used to handle a mail stream of flyers of relatively less thickness. The necessity of using separate mail streams based on equipment limitations results in the loss of bulk mailing discounts that may exceed, for example, $60 per thousand pieces mailed.
Co-mailing has been used to obtain postal discounts by bundling the mailing pieces of different physical configurations. In some traditional methods, co-mailing is an off line process in which two or more complete books (e.g., catalogs, flyers, etc.) are merged together using a piece of equipment called a co-mailer. A traditional method to commingle a book with flyers and other promotional materials involves using an on-serting process. On-serting is typically used to deposit flyers or other promotional materials onto a book, all of which are intended to be delivered to the same recipient.